Method of making footballs



Nov. 24,1942. w. J. von' Erm. ,3

amaon or IAKIHG roo'mms Filed Sept. 3. 1940 ii Patented Nov. 2 1942vUNITED STATE 5 PAT-EN T ome METHOD OF MAKING FOOTBALLS I William J.Volt, Los Angeles, and Leltli C. Welmer, Southgate, Calm; said Weimerassignor to said Volt Application September a, 1940, Serial No. 355,1767 Claims. (CL 154-16) present undulations-interfering with the properThis invention relates to a method of making footballs and ,other hollowinflatable athletic play balls.

innermost layer isadapted to receive and retain the air of inflation. Anoutermost layer is The walls of athletic play balls of this type are.usually built up of a number of layers, each layer 7 being adapted tofulfill a distinctive purpose. An

adapted to resist wear and abrasion caused by contact of the ball withexternal objects, and an.

intermediate layer or layers are adapted to provide additional materialto resist puncture and to strengthen the ball against enlargement indiameter under the pressure of inflation. All of the several layers bytheir composition and in their relationship toeach other are adapted togive the ball the requisite play qualities as to resiliency and inotherrespects.

A layer of wound stranded material, such as fibrous thread or cord, hasbeen found to be effective 'to serve as an intermediate reinforcing.layer between the air retaining innermost layer and the outermostprotective covering layer.

. Sometimes this stranded material is wound upon the ball in greatcircles, or near great circles, the crossing points of the circles beingscattered and rather generally distributed over the surface of the balL,In other cases the stranded'material is spirally wound about an axis ofthe ball as a center, the winding beginning at or adjacent one pole ofthis axis and terminating at the other pole thereof. In the manufactureof footballs, a spiral winding of this character is about the long axisof the football, it being obviously impractical to wind strandedmaterial in elliptisigned to feed the stranded material at a uniformtension to the ball. But unless the wall of the ball to which thestranded material is being fed is substantially rigid, it will betemporarily depressed and furrowed by the stranded material at the pointof winding contact with the result performance of the ball when placedin use.

It has been the practice to attain the desired rigidity of the wall ofthe ball upon which the stranded material is wound, by building the ballupon a form of solid material; This form is later removed through anopening in the ball which must be left in the layer or envelopeofwvound,-

stranded material as well as in any layers of the ball beneaththe-winding. Either provision is madefor lacing this opening, or theopening is permanently closed at later stages ofmanufacture of the ball.The method of employing a rigid form to ensure even winding of thestranded material upon the ball obviously presents several difilculties,and the resultant product has disadvantages no matter which methodofclosing the opening for the form is used.

that the wound ball will be misshapen and will as It is one object ofthis invention'to provide rigidity in the foundation wall upon whichstranded material isto be wound,.in summer which shall obviate thedifilculties and disadvantages attendant upon the use of a solid re-'movable form.

It is another object to afford arapid inexpensive and simple method ofwinding at even 4 tension a stranded material upon a ball core orfoundation.

It is another object to provide a method of manufacturinga ball whichwill produce a ball which will not lose its original shape or size,which will be durable, and which will have the requisite playcharacteristics.

The invention is herein described in connec- .tion with the manufactureof a football. In some respects the invention is, applicable to themanufacture of hollow, inflatable athletic footballs of other thanthe'ellipsoidal'shape of th' standard football. 1

In the drawingi Fig. l is a vertical, sectional view of a disposedwithin a curing mold.

Fig. 2 is an elevational view illustrating sthe manner in which areinforcing wall is applied to the bladder.

l 'lg. 3 is a vertical section taken along the line I 3-3 of Fig. 2. v

Flg. 4 is an elevational view illustrating the manner in which strandedmaterial is next wound upon the ball.

Fig. 5 shows the completed ball with resisting cover applied thereto. IThe first step in the manufacture of the football is the making' of theair-retaining innermost a wearlayer of the ball, commonly called thebladder.

bladder.

bladder ll through the valve which may be rubberized, are then,

2 This may be made in any suitable manner, but preferably pieces ofrelatively thin sheeted rubber or otherrubber-like material are securedtogether along their marginal edges in the shape of a football to forman air-retaining bladder l I. An inflation valve 12 of a suitablecharacter is securedin place in the bladder ll. preferably at a placemidway of the ends it and ll of the bladder; The bladder is then placedin a mold l5 provided with air-conveying means l6, by which air may beforced into the interior of the [2. The bladder is then inflated andwhile under inflation is subjected to a heat cure, which hardens therubber material ofthe bladder and gives it the deflnite form ofastandard football. I

, Air pressure in the bladder is removed; the bladder is taken from themold and reinflated to a size somewhat less than that desired for thecompleted football. Pieces ll of woven fabric,

adhesively applied to the inflated bladder preferably with lappedmarginal joints. These pieces may be of any number and configuration,but it has been found satisfactory to cover the entire surface of thebladder with at least four similarly shaped and equally dimensionedpieces ILeach extending from the end "to the end I of the football.

In applying the pieces II to the bladder, the

bladder may be. initially dipped in latex or similar material, or rubbercement may be applied to the under surface of the pieces "beforeapplication to the bladder.

The fabric covered bladder is next placed in a mold of slightly largerdimensions than the mold IE, but otherwise similar thereto. In this moldthe ball is inflated by air at a relatively high pressure, for example90 to 100 pounds, which forces the wall of the ball into intimatecontact with the inner surface of the mold, stretching the fabricmaterial of the pieces l'l. While thus inflated and while the pieces Hare in stretched condition, the ball is given a heat-cure, which fixesit in shape and size.

The ball is now deflated sufliciently for removal from the mold andagain inflated to a relatively high pressure. When thus inflated itpresents at all points a hard unyielding surface, which can only bedented by the application of a very heavy inward thrusting stress. Theball is now placed in a winding machine and thread or cord, -or otherstranded material I8 is spirally wound upon it, beginning at a point theball and terminating at-a point near the other end or pole ll of theball. This cord is preferably rubberized.

End caps 2i and- 22, consisting of small concave-convex pieces of rubberor rubberized fab- |9 near the pole IQ of .properly cured. It is to thecover flowed into the space between the ball and the mold, andvulcanizingly united to the ball in the usual manner.

The mold for this last vulcanization may be formed with impressions tocast in the surface of the rubbercover of the ball any desired markingssuch as simulations 24 of the lacing of a leather ball, these markingsfacilitating the handling of the ball by the players as well asimproving the appearance of the ball.

Or, a leather cover may be given the ball by adhesively' applying to thecord-wound carcass a plurality of leather panels, and thereafterpreferably giving the leather covered ball a pressure treatment in amold preferably at a low temperature.

The process is subject to a number of variations without departing fromthe spirit of the invention. While, as described above, the ball isgiven a vulcanizing cure after each application of material thereto, oneor more of these vulcanizing steps may be omitted from the process,provided that when the ball is completed the rubber material of all ofits parts has been be preferred, however, that the bladder be at leastpartially cured before the application of the pieces of fabric, and itis also preferable that the fabric covered ball be enlarged somewhat byinternal air pressure and that the rubber material of the fabric becured while the fibers thereof are in their stretched condition. Theword rubber as herein used is meant to include not only natural rubberbut synthetic materials having the reprising: making a ric, areadhesively applied to the ball at its rell. These polar caps havethickness as the diameter of the stranded material I! if the latter iswound upon the ball in a single ply, or as the total thickness of thelayer of cord windings, if there is more than one ply of windings.

The cord wound ball may now be given a heatcure in a mold and afterwardprovided with a wean-resisting cover, or it may be provided with thecover without an intermediate molding cure. The wear-resisting cover maybe a one-piece rubber envelope 23 formed by vulcanizing in place uponthe ball a plurality of pieces of rubberg or the ball may be mountedwithin a mold and in spaced relationship with the internal surface ofthe mold and a spective ends I! and substantially the same liquid rubbermaterial for silient character of rubber such as materials classed as"synthetic rubber.

We claim as our invention:

l. A method of making an athletic ball, comvalved air-retaining bladderof rubber-like material; inflating said bladder to a relatively lowpressure .and to a size slightly smaller than that of the completedball; bondin to said inflatedbladder an envelope of fabric wovenmaterial highly resistant to tensile stresses; inflating said envelopedbladder without substantial enlargement to a substantially higherpressure sumcient to substantially resist the inwardly directed stressesapplied thereto during the operation of winding at a substantial tensiona reinforcing layer of stranded material thereon; winding strandedmaterial at a substantial tension on and bonding it to said inflatedbladder to form a reinforcing layer; and applying and bonding awear-resisting cover to said ball.

2. A method of making an athletic ball, comprising: making a valvedair-retaining bladder of rubber-like material; inflating said bladder toa relatively low pressure and to a size slightly smaller than that ofthe completed bail; bonding to said inflated bladder an envelope offabric woven material highly resistant to tensile stresses; inflatingsaid enveloped bladder without substantial enlargement to asubstantially higher pressure suflicient'to substantially resist theinwardly directed stresses applied thereto during the operation ofwinding at a substantial tension a. reinforcing layer of strandedmaterial thereon; spirally winding stranded material at a substantialtension on and bonding it to said inflated enveloped bladder betweenopposite poles to form 'a reinforcing layer; and applying and bonding awear-resisting cover to said ball.

3. A method of making an ellipsoidal football, comprising: making arelatively thin walled incured pieces of fabric material highlyresistant to tensile stresses; inflating said fabric covered bladderwithout substantial enlargement to a substantially higher pressuresuflicient to render inwardly it locally substantially unyieldable whensubjected to the stresses arising from winding thereon stranded materialat a substantial feed tension adequate for properly forming areinforcing envelope of stranded material;

subiected to the stresses arising from winding thereon stranded materialat a substantial feed tension adequate for properly forming areinforcing envelope of stranded-material; spirally winding on theinflated fabric covered ball rubberized stranded material at substantialtension and about the long axis of the ball; applying a wear-resisting,rubber cover to the ball; and giv ing the ball a vulcanizing cure in amold.

6. A method of making an ellipsoidal football,

comprising: making a relatively thin walled mflatable bladder of rubbermaterial having an inflation valve, and in the shape of the completedarticle; inflating said bladder to a relaspirally winding strandedmaterial on the inflated fabric covered bladder at a substantial tensionand about the long axis of-the bladder; applying a wear-resistingcovering envelope to the ball; and giving the ball a vulcanizing cure ina mold.

4. A method of making an ellipsoidal football,

comprising: making a relatively thin walled inflatable bladder of curedrubber material having an inflation valve, and in the shape of thecompleted article; inflating said bladder to a relatively low pressureand to a size slightly smaller than that of the completed ball; applyingthere- 'to with a vulcanizable rubber adhesive an envelope of marginallysecured, lune-shaped pieces of rubberized fabric material highlyresistant to tensile stresses; inflating said fabric covered bladderwithout substantial enlargement to a substantially higher pressuresufficient to render it locally substantially unyieldable inwardly whensubjected to the stresses arising from winding thereon stranded materialat a. substantial feed tension adequate for properly forming areinforcing envelope of stranded material; spirally winding on theinflated fabric covered bladder rubberized stranded material at asubstantial tension and about the long axis of the bladder; curing theball in a mold; and applying a wear-resisting cover to the ball.

5. A method of making an ellipsoidal football, comprising: making arelatively thin walled inflatable ball of cured rubber material havingan inflation valve, and in the shape of the completed article; inflatingsaid ball to a relatively low pressure and to a size slightly smallerthan that of the completed ball; applying thereto' with a vulcanizablerubber adhesive an envelope of marginally secured, lune-shaped pieces ofrubberized fabric material highly resistant to tensile stresses;inflating said fabriccovered ball without substantial enlargement to asubstantially higher pressure sufllcient to render it 10- callysubstantially unyieldable inwardly when tively low pressure and to asize slightly smaller than that of the completed ball; applying thereto,with a vulcanizable rubber adhesive, an envelope of marginally securedpieces of rubberized fabric material highly resistant to tensilestresses; vulcanizing said envelope and bladder; I

inflating said fabric covered. bladder without substantial enlargementto a substantially higher pressure suflicient to render it locallysubstantially, unyieldable inwardly when subjected to the stressesarising from winding thereon stranded material at a substantial feedtension adequate for properly forming a reinforcing envelope of strandedmaterial; spirally winding on the inflated fabric covered bladderrubberized stranded material at a substantial tension and about the longaxis of the bladder; curing the ball in a mold; and applying awear-resisting cover to the ball.

7. A method of making an ellipsoidal football, comprising: making arelatively thin walled inflatable bladder of rubber material having aninflation valve, and in the shape of the com-- pleted article; inflatingsaid bladder to a relatively low pressure and to a size slightly smallerthan that of the completed ball; applying thereto by meansofvulcanizable rubber adhesive and withmarginally lapped joints, piecesof fabric material highly resistant to tensile stresses to form anenvelope; inflating said fabric covered bladder without substantialenlargement to a substantially higher pressuressuflicient to render itlocally substantially unyieldable inwardly when subjected to thestresses arising from winding thereon stranded material at a substantialfeed tension adequate for properly forming a reinforcing envelope ofstranded material; spirally'windlng stranded material on the inflatedfabric covered bladder at a substantial tension and-about the long axisof the bladder;

applying a wear-resisting covering envelope tothe ball; and giving theball a vulcanizing cure in a mold.

WILLIAM J. VOIT. LEI'II-I C. WEHMER.

